Old RSS link removed with new RSS link in documentation

Old RSS link (http://bakery.cakephp.org/articles/rss) removed from documentation. And new RSS link (http://bakery.cakephp.org/articles.rss) has been replaced with old link. 
We should update the link otherwise if any novice user copy and paste from the old documents then he can get `Error: An Internal Error Has Occurred.` type error what I faced today.
[Existing documentation XML page](http://book.cakephp.org/2.0/en/core-utility-libraries/xml.html)
Merge pull request #782 from shahariaazam/master

Old RSS link removed with new RSS link in documentation